Results 51 to 60 of about 2,944 (214)

Long-lived planetesimal discs [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society, 2010
We investigate the survival of planetesimal discs over Gyr timescales, using a unified approach that is applicable to all Keplerian discs of solid bodies -- dust grains, asteroids, planets, etc. Planetesimal discs can be characterized locally by four parameters: surface density, semi-major axis, planetesimal size and planetesimal radial velocity ...
Kevin Heng, Scott Tremaine
openaire   +4 more sources

Role of Magma Ocean Differentiation in the Formation and Long‐Term Preservation of Distinct Geochemical Domains Within the Deep Mantle

open access: yesGeochemistry, Geophysics, Geosystems, Volume 26, Issue 5, May 2025.
Abstract We modeled the evolution of the terrestrial Magma Ocean using the short‐lived 182Hf‐182W isotope system (t1/2 = 8.9 Myr) in a multi‐reservoir early Earth. We start with a chondritic Earth at T0 = 4.567 Ga. Core segregates and attains its present‐day mass, W elemental and isotopic (182W/184W) composition by the end of core formation (TCF).
Seema Kumari, Ramananda Chakrabarti
wiley   +1 more source

Magnetization of Iron Meteorites up to the Meter in Size as Possible Analogs for Asteroid Psyche

open access: yesJournal of Geophysical Research: Planets, Volume 130, Issue 4, April 2025.
Abstract Meteorite paleomagnetic studies indicate planetesimal generated magnetic fields, but spacecraft magnetic measurements have yet to identify asteroidal natural remanent magnetization (NRM). This apparent discrepancy is of particular interest in the context of the NASA Psyche mission, which will search for evidence of past magnetic activity of ...
Clara Maurel   +6 more
wiley   +1 more source

Dust Clumping in Outer Protoplanetary Disks: The Interplay among Four Instabilities

open access: yesThe Astrophysical Journal Letters
Dust concentration in protoplanetary disks (PPDs) is the first step toward planetesimal formation, a crucial yet highly uncertain stage in planet formation.
Pinghui Huang, Xue-Ning Bai
doaj   +1 more source

Volatile-to-sulfur Ratios Can Recover a Gas Giant’s Accretion History

open access: yesThe Astrophysical Journal Letters, 2023
The newfound ability to detect SO _2 in exoplanet atmospheres presents an opportunity to measure sulfur abundances and so directly test between competing modes of planet formation. In contrast to carbon and oxygen, whose dominant molecules are frequently
Ian J. M. Crossfield
doaj   +1 more source

Shock‐heated graphite in three IAB iron meteorites—Implications on the formation of diamond

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 4, Page 744-756, April 2025.
Abstract Iron meteorites, originating from the deepest parts of their parent bodies and separated during major break‐up events, surprisingly rarely contain diamonds despite experiencing similar pressure–temperature conditions as diamond‐bearing ureilites. In this study, graphite from three non‐magmatic IAB iron meteorites Canyon Diablo, Campo del Cielo,
Oliver Christ   +7 more
wiley   +1 more source

Mechanochemical Reactivity of Ribonucleosides Mediated by Inorganic Species: Implications for Extraterrestrial Organic Matter Interpretation

open access: yesApplied Sciences
Metal species and carbonate are often found as minerals in extraterrestrial rocky bodies. Based on this, the mechanochemical-induced degradation of canonical purine and pyrimidine ribonucleosides into their corresponding nucleobases mediated by some of ...
Gustavo P. Maia   +7 more
doaj   +1 more source

When and why formation of large bodies in circumstellar discs could take place?

open access: yesEPJ Web of Conferences, 2013
We outlined the scenario of the planetary system formation, where large bodies are formed on the stage of massive discs. On this stage the whole of factors: chemical composition, chemical catalytic reactions, the disc self- gravitation, the increased ...
Stadnichenko Olga A.   +2 more
doaj   +1 more source

The Oxygen Isotopic Composition of Samples Returned from Asteroid Ryugu with Implications for the Nature of the Parent Planetesimal

open access: yesThe Planetary Science Journal, 2023
We present oxygen isotopic analyses of fragments of the near-Earth C _b -type asteroid Ryugu returned by the Hayabusa2 spacecraft that reinforce the close correspondence between Ryugu and CI chondrites.
Haolan Tang   +89 more
doaj   +1 more source

The Meteoritical Society: Business from 2023 to 2024

open access: yes
Meteoritics &Planetary Science, Volume 60, Issue 3, Page 680-696, March 2025.
Nancy L. Chabot   +2 more
wiley   +1 more source

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